Metal–organic framework (MOF) nanosheets could serve as ideal building blocks of molecular sieve membranes owing to their structural diversity and minimized mass‐transfer barrier. To date, discovery ...of appropriate MOF nanosheets and facile fabrication of high performance MOF nanosheet‐based membranes remain as great challenges. A modified soft‐physical exfoliation method was used to disintegrate a lamellar amphiprotic MOF into nanosheets with a high aspect ratio. Consequently sub‐10 nm‐thick ultrathin membranes were successfully prepared, and these demonstrated a remarkable H2/CO2 separation performance, with a separation factor of up to 166 and H2 permeance of up to 8×10−7 mol m−2 s−1 Pa−1 at elevated testing temperatures owing to a well‐defined size‐exclusion effect. This nanosheet‐based membrane holds great promise as the next generation of ultrapermeable gas separation membrane.
MOF nanosheet membranes: Layered Zn2(benzimidazole)3(OH)(H2O) precursors were exfoliated into nanosheets with high aspect ratio. These were further assembled on anisotropic α‐Al2O3 substrates for the construction of high‐performance molecular‐sieve membranes. The membranes feature high H2/CO2 selectivity and excellent H2 permeance. Zn green, N orange, C gray, O red.
Lesion studies link the prefrontal cortex (PFC) to executive functions. However, the evidence from in vivo investigations in healthy people is mixed, and there are no quantitative estimates of the ...association strength. To examine the relationship between PFC volume and cortical thickness with executive cognition in healthy adults, we conducted a meta-analysis of studies that assessed executive functions and PFC volume (31 samples,) and PFC thickness (10 samples) in vivo, N=3272 participants. We found that larger PFC volume and greater PFC thickness were associated with better executive performance. Stronger associations between executive functions and PFC volume were linked to greater variance in the sample age but was unrelated to the mean age of a sample. Strength of association between cognitive and neuroanatomical indices depended on the executive task used in the study. PFC volume correlated stronger with Wisconsin Card Sorting Test than with digit backwards span, Trail Making Test and verbal fluency. Significant effect size was observed in lateral and medial but not orbital PFC. The results support the "bigger is better" hypothesis of brain-behavior relation in healthy adults and suggest different neural correlates across the neuropsychological tests used to assess executive functions.
Metal‐organic framework (MOF) nanosheets are promising membrane building blocks for ultimate and efficient separation because of the diversified structures, ultrathin thickness, and tunable chemical ...functionalities. Targeting at membrane‐based separation, representative developments of top‐down and bottom‐up methods to produce high‐quality MOF nanosheets are introduced, and the merits and demerits of each method are carefully elucidated. A summary of fabrication approaches of MOF nanosheet‐based membranes is also put forward to establish a comprehension on the relationship between membrane structure and the eventual separation performance. Moreover, classical characterization techniques to get an insight into these 2D materials are addressed. Last but not least, concerns on the challenges and opportunities for these novel membranes are demonstrated in order to provide some guidelines for the development in the future.
Metal‐organic framework (MOF) nanosheets have great potential to serve as state‐of‐the‐art building units of membranes for precise and ultimate separation. This review provides a comprehensive summary of the separation application‐oriented progresses of MOF nanosheets. The top‐down and bottom‐up fabrication of disintegrated MOF nanosheets, nanosheet assembly into selective membranes, characterizations, and preliminary separation–performance relationship are presented.
The nucleus accumbens (NAc) is a subcortical brain structure known primarily for its roles in pleasure, reward, and addiction. Despite less focus on the NAc in pain research, it also plays a large ...role in the mediation of pain and is effective as a source of analgesia. Evidence for this involvement lies in the NAc's cortical connections, functions, pharmacology, and therapeutic targeting. The NAc projects to and receives information from notable pain structures, such as the prefrontal cortex, anterior cingulate cortex, periaqueductal gray, habenula, thalamus, etc. Additionally, the NAc and other pain-modulating structures share functions involving opioid regulation and motivational and emotional processing, which each work beyond simply the rewarding experience of pain offset. Pharmacologically speaking, the NAc responds heavily to painful stimuli, due to its high density of μ opioid receptors and the activation of several different neurotransmitter systems in the NAc, such as opioids, dopamine, calcitonin gene-related peptide, γ-aminobutyric acid, glutamate, and substance P, each of which have been shown to elicit analgesic effects. In both preclinical and clinical models, deep brain stimulation of the NAc has elicited successful analgesia. The multi-functional NAc is important in motivational behavior, and the motivation for avoiding pain is just as important to survival as the motivation for seeking pleasure. It is possible, then, that the NAc must be involved in both pleasure and pain in order to help determine the motivational salience of positive and negative events.
Layered metal-organic frameworks would be a diverse source of crystalline sheets with nanometer thickness for molecular sieving if they could be exfoliated, but there is a challenge in retaining the ...morphological and structural integrity. We report the preparation of 1-nanometer-thick sheets with large lateral area and high crystallinity from layered MOFs. They are used as building blocks for ultrathin molecular sieve membranes, which achieve hydrogen gas (H2) permeance of up to several thousand gas permeation units (GPUs) with H2/CO2 selectivity greater than 200. We found an unusual proportional relationship between H2 permeance and H2 selectivity for the membranes, and achieved a simultaneous increase in both permeance and selectivity by suppressing lamellar stacking of the nanosheets.
Materials with hysteretic multi‐step spin‐crossover (SCO) have potential application in high‐order data storage. Here, an unprecedented hysteretic four‐step SCO behavior with the sequence of ...LS↔HS0.25LS0.75↔HS0.5LS0.5↔ HS0.75LS0.25↔HS is found in a three‐dimensional (3D) Hofmann‐type metal–organic framework (MOF), which is evidenced by magnetic, differential scanning calorimetry, and crystal data. Further experiments involving guest exchange leads to the first reversible modulation of four‐, two‐, and one‐stepped SCO behaviors, which provides a new strategy for developing multi‐step SCO materials.
Hysteretic four‐step SCO behavior, LS↔HS0.25LS0.75↔HS0.5LS0.5↔HS0.75LS0.25↔HS, is evidenced by magnetic, differential scanning calorimetry, and crystal data. Furthermore, reversible modulation of four‐, two‐, and one‐stepped SCO behaviors is realized through guest exchange.
Ethnic dance is a part of minority culture and an important chapter of intangible cultural heritage. Because the art of dance does not exist in a certain physical form in a certain environment, it is ...difficult to record and preserve dance. In traditional recording work, dancers' dance movements are mostly recorded through text, photos, videos, etc. However, these methods can only record and preserve dance movements in a two-dimensional manner from a limited number of angles and cannot achieve accurate and comprehensive record protection of dance poses. Moreover, data preserved by traditional methods can only be simply copied and transferred, and cannot be exploited, developed, or innovated. Therefore, motion capture technology can be applied to the protection of ethnic dance art, and motion capture technology can be used to obtain 3D gestures of ethnic minority dance spaces, restore and optimize digital movements, such as establishing a national dance art movement technology database, and combine the protection of the original ecological cultural atmosphere. It can accurately and comprehensively preserve the essence of ethnic minority dance art and provide effective reference for many ethnic minority dances with ethnic characteristics, digital protection of sports, and the future.
Ocular drug delivery has been a major challenge for clinical pharmacologists and biomaterial scientists due to intricate and unique anatomical and physiological barriers in the eye. The critical ...requirement varies from anterior and posterior ocular segments from a drug delivery perspective. Recently, many new drugs with special formulations have been introduced for targeted delivery with modified methods and routes of drug administration to improve drug delivery efficacy. Current developments in nanoformulations of drug carrier systems have become a promising attribute to enhance drug retention/permeation and prolong drug release in ocular tissue. Biodegradable polymers have been explored as the base polymers to prepare nanocarriers for encasing existing drugs to enhance the therapeutic effect with better tissue adherence, prolonged drug action, improved bioavailability, decreased toxicity, and targeted delivery in eye. In this review, we summarized recent studies on sustained ocular drug/gene delivery and emphasized on the nanocarriers made by biodegradable polymers such as liposome, poly lactic-co-glycolic acid (PLGA), chitosan, and gelatin. Moreover, we discussed the bio-distribution of these nanocarriers in the ocular tissue and their therapeutic applications in various ocular diseases.
The retina is a specialized neural tissue that senses light and initiates image processing. Although the functional organization of specific retina cells has been well studied, the molecular profile ...of many cell types remains unclear in humans. To comprehensively profile the human retina, we performed single‐cell RNA sequencing on 20,009 cells from three donors and compiled a reference transcriptome atlas. Using unsupervised clustering analysis, we identified 18 transcriptionally distinct cell populations representing all known neural retinal cells: rod photoreceptors, cone photoreceptors, Müller glia, bipolar cells, amacrine cells, retinal ganglion cells, horizontal cells, astrocytes, and microglia. Our data captured molecular profiles for healthy and putative early degenerating rod photoreceptors, and revealed the loss of MALAT1 expression with longer post‐mortem time, which potentially suggested a novel role of MALAT1 in rod photoreceptor degeneration. We have demonstrated the use of this retina transcriptome atlas to benchmark pluripotent stem cell‐derived cone photoreceptors and an adult Müller glia cell line. This work provides an important reference with unprecedented insights into the transcriptional landscape of human retinal cells, which is fundamental to understanding retinal biology and disease.
Synopsis
The transcriptome of human neural retina at a single‐cell level defines the gene expression profile in major cell types in the neural retina and can be used as a benchmark to assess the quality of stem cell‐derived cells or primary retinal cells.
The presented transcriptome atlas of human neural retina comprises single‐cell RNA‐sequencing data from 20,009 human retinal cells.
Unsupervised cell clustering analysis allows identification of 18 transcriptionally distinct cell populations that represent all known neural retinal cell types.
Reduced expression of the long non‐coding RNA MALAT1 correlates with longer post‐mortem time in putative early degenerating rod photoreceptors.
The retina transcriptome atlas can be used to benchmark pluripotent stem cell‐derived cone photoreceptors and an adult Müller glia cell line.
A comprehensive analysis of the human retinal transcriptome at a single‐cell level defines gene expression profiles of all major retinal cell types.
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